/*
 * Copyright (c) 1985 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that: (1) source distributions retain this entire copyright
 * notice and comment, and (2) distributions including binaries display
 * the following acknowledgement:  ``This product includes software
 * developed by the University of California, Berkeley and its contributors''
 * in the documentation or other materials provided with the distribution
 * and in all advertising materials mentioning features or use of this
 * software. Neither the name of the University nor the names of its
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include "config.h"
#include "sys.h"
#include "nameser.h"
#include "resolv.h"

/*
 * Form all types of queries.
 * Returns the size of the result or -1.
 */
res_mkquery (op, dname, class, type, data, datalen, newrr, buf, buflen)
     int op;	   /* opcode of query */
     char *dname;  /* domain name */
     int class, type;	/* class and type of query */
     char *data;   /* resource record data */
     int datalen;  /* length of data */
     struct rrec *newrr;	/* new rr for modify or append */
     char *buf;	   /* buffer to put query */
     int buflen;   /* size of buffer */
{
    register HEADER *hp;
    register char *cp;
    register int n;
    char *dnptrs[10], **dpp, **lastdnptr;

#ifdef DEBUG
    if (_res.options & RES_DEBUG)
	printf ("res_mkquery(%d, %s, %d, %d)\n", op, dname, class, type);
#endif /*DEBUG */
    /*
     * Initialize header fields.
     */
    if ((buf == NULL) || (buflen < sizeof (HEADER)))
	return (-1);
    bzero (buf, sizeof (HEADER));
    hp = (HEADER *) buf;
    hp->id = htons (++_res.id);
    hp->opcode = op;
    hp->pr = (_res.options & RES_PRIMARY) != 0;
    hp->rd = (_res.options & RES_RECURSE) != 0;
    hp->rcode = NOERROR;
    cp = buf + sizeof (HEADER);
    buflen -= sizeof (HEADER);
    dpp = dnptrs;
    *dpp++ = buf;
    *dpp++ = NULL;
    lastdnptr = dnptrs + sizeof (dnptrs) / sizeof (dnptrs[0]);
    /*
     * perform opcode specific processing
     */
    switch (op) {
    case QUERY:
	if ((buflen -= QFIXEDSZ) < 0)
	    return (-1);
	if ((n = dn_comp (dname, cp, buflen, dnptrs, lastdnptr)) < 0)
	    return (-1);
	cp += n;
	buflen -= n;
	putshort (type, cp);
	cp += sizeof (u_short);
	putshort (class, cp);
	cp += sizeof (u_short);
	hp->qdcount = htons (1);
	if (op == QUERY || data == NULL)
	    break;
	/*
	 * Make an additional record for completion domain.
	 */
	buflen -= RRFIXEDSZ;
	if ((n = dn_comp (data, cp, buflen, dnptrs, lastdnptr)) < 0)
	    return (-1);
	cp += n;
	buflen -= n;
	putshort (T_NULL, cp);
	cp += sizeof (u_short);
	putshort (class, cp);
	cp += sizeof (u_short);
	putlong (0, cp);
	cp += sizeof (u_long);
	putshort (0, cp);
	cp += sizeof (u_short);
	hp->arcount = htons (1);
	break;

    case IQUERY:
	/*
	 * Initialize answer section
	 */
	if (buflen < 1 + RRFIXEDSZ + datalen)
	    return (-1);
	*cp++ = '\0';		  /* no domain name */
	putshort (type, cp);
	cp += sizeof (u_short);
	putshort (class, cp);
	cp += sizeof (u_short);
	putlong (0, cp);
	cp += sizeof (u_long);
	putshort (datalen, cp);
	cp += sizeof (u_short);
	if (datalen) {
	    bcopy (data, cp, datalen);
	    cp += datalen;
	}
	hp->ancount = htons (1);
	break;

#ifdef ALLOW_UPDATES
	/*
	 * For UPDATEM/UPDATEMA, do UPDATED/UPDATEDA followed by UPDATEA
	 * (Record to be modified is followed by its replacement in msg.)
	 */
    case UPDATEM:
    case UPDATEMA:

    case UPDATED:
	/*
	 * The res code for UPDATED and UPDATEDA is the same; user
	 * calls them differently: specifies data for UPDATED; server
	 * ignores data if specified for UPDATEDA.
	 */
    case UPDATEDA:
	buflen -= RRFIXEDSZ + datalen;
	if ((n = dn_comp (dname, cp, buflen, dnptrs, lastdnptr)) < 0)
	    return (-1);
	cp += n;
	putshort (type, cp);
	cp += sizeof (u_short);
	putshort (class, cp);
	cp += sizeof (u_short);
	putlong (0, cp);
	cp += sizeof (u_long);
	putshort (datalen, cp);
	cp += sizeof (u_short);
	if (datalen) {
	    bcopy (data, cp, datalen);
	    cp += datalen;
	}
	if ((op == UPDATED) || (op == UPDATEDA)) {
	    hp->ancount = htons (0);
	    break;
	}
	/* Else UPDATEM/UPDATEMA, so drop into code for UPDATEA */

    case UPDATEA:		  /* Add new resource record */
	buflen -= RRFIXEDSZ + datalen;
	if ((n = dn_comp (dname, cp, buflen, dnptrs, lastdnptr)) < 0)
	    return (-1);
	cp += n;
	putshort (newrr->r_type, cp);
	cp += sizeof (u_short);
	putshort (newrr->r_class, cp);
	cp += sizeof (u_short);
	putlong (0, cp);
	cp += sizeof (u_long);
	putshort (newrr->r_size, cp);
	cp += sizeof (u_short);
	if (newrr->r_size) {
	    bcopy (newrr->r_data, cp, newrr->r_size);
	    cp += newrr->r_size;
	}
	hp->ancount = htons (0);
	break;

#endif /* ALLOW_UPDATES */
    }
    return (cp - buf);
}
